MHT CET202616 April 2026Evening ShiftChemistryd and f Block ElementsActual
What is the oxidation state of chromium in the final product when KI reacts with acidified potassium dichromate solution?
Options
- A+2
- B+3
- C+6
- D+4
Correct answer
B. +3
Step-by-step solution
Potassium dichromate ( K₂Cr₂O₇ ) acts as a strong oxidizing agent in an acidic medium. It oxidizes iodide ions ( I^- ) from KI to iodine ( I₂ ) and itself gets reduced to chromium(III) ions ( Cr³⁺ ). The ionic equation for the reaction is: Cr₂O₇²⁻ + 14H^+ + 6I^- 2Cr³⁺ + 3I₂ + 7H₂O In the final product, chromium is present as Cr³⁺ . Therefore, the oxidation state of chromium in the final product is +3 . Answer: +3